This invention relates generally to a rigid apparatus and a method for its use in joining sheets of material at their edges. More specifically, the invention relates to a mechanical fastener effective to join panels of material at butt joints without destroying or removing the panels.
Many industrial facilities, particularly nuclear power plants, require the installation of fire barrier panels on cable trays. Often due to their wear and aging, and particularly during the course of a plant shut-down, the backfitting of butt joint panels of fire barrier material which have been previously installed on cable trays is necessary. Options available to persons carrying out such maintenance would ordinarily involve upgrading of panels during "backfitting" of the butt joint by tying with stainless steel wire loops. However, such a process would involve removal of one panel to gain access into the enclosure in order to feed the inserted end of the wire back out through the free panel. The stitch and tie method is depicted by FIG. 1 and FIG. 2. In carrying out a stitching and tying method, holes for the loops would need to be pre-drilled. Moreover, significant damage or destruction of panels removed is likely during such a maintenance procedure. The stitching method clearly has numerous drawbacks and disadvantages.
Bolts and plates having flat circular heads provided with spikes have been shown in the art, for example in U.S. Pat. No. 3,019,887, issued Feb. 6, 1962 to G. Lowden. The spikes provided in these devices are intended to prevent the plate or bolt from rotating once in place. The spikes of such prior devices are intended to facilitate the introduction and tightening of a nut or the like. Such devices are not useful in the present application, where one side of panels to be joined are inaccessible once the panels are placed in position. Nor are such prior devices operable in the environment in which the present invention is intended. Securing panels at butt-type joints is a problem to be separately addressed in the art, and has yet to find suitable solutions, prior to the present invention.
From the above it is seen that an improved device and method of securing sheet panels of material at their butt joints is desired.